The present invention is directed to bicycles and, more particularly, to a bicycle control device with combined operation of multiple output elements.
Conventional bicycles have either internal or external transmissions. Internal transmissions usually include a planetary gear mechanism mounted inside the hub of the rear wheel, wherein the planetary gear mechanism changes the gear ratio of the transmission in response to movement of a lever mounted to the handlebar. External transmissions usually comprise a plurality of front sprockets mounted to the pedal crank, a front derailleur mounted to the bicycle frame, a plurality of rear sprockets mounted to the rear wheel, and a rear derailleur mounted to the bicycle frame. The front derailleur switches the drive chain among the plurality of front sprockets in response to movement of one or more front derailleur control levers mounted to the handlebar, and the rear derailleur switches the drive chain among the plurality of rear sprockets in response to movement of one or more rear derailleur control levers mounted to the handlebar.
Recently, the functions of an internal bicycle transmission and an external bicycle transmission have been combined. In such systems, a planetary gear mechanism is mounted inside the rear wheel hub, a plurality of rear sprockets are mounted to the rear wheel, and a rear derailleur is mounted to the bicycle frame. The planetary gear mechanism provides an internal transmission component (usually called an internal hub transmission), and the plurality of rear sprockets and rear derailleur provide an external transmission component. The planetary gear mechanism changes the gear ratios in the internal transmission component in response to movement of one or more internal transmission control levers mounted to the handlebar, and the rear derailleur switches the drive chain among the plurality of rear sprockets to change gear ratios in the external transmission component in response to movement of one or more external transmission control levers mounted to the handlebar.
In known bicycles that have multiple transmission components, such as front/rear derailleurs and combined internal/external transmissions, one transmission component is operated by one dedicated control device, and the other transmission component is operated by another dedicated control device. This increases the complexity of the overall bicycle transmission, and it requires the rider to remember which transmission component to operate to achieve a desired gear ratio. Sometimes it is necessary for the rider to operate both transmission components substantially simultaneously to achieve a desired gear ratio. This can make it very difficult for even an experienced cyclist to ride the bicycle effectively.
Sometimes a transmission gear indicator is provided with each transmission so that the rider knows the state of the transmission. Since a separate gear indicator is provided for each transmission, the rider must contemplate the information provided by multiple gear indicators whenever two external transmissions or combined internal/external transmissions are provided on the bicycle. This makes it very difficult to obtain a sense of the overall gear ratio provided by the multiple transmissions.